BACKGROUND In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The implications of this unique arrangement on infradiaphragmatic venous physiology are poorly understood. METHODS AND RESULTS We studied the effects of respiration and gravity on infradiaphragmatic venous flows in 20 normal healthy volunteers (control) and 48 Fontan patients (atriopulmonary conne...

Interaction among potential vorticity perturbations and propagating internal gravity waves in a horizontally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating gravity waves while the density component of the potential vorticity perturbation is significantly amplified, potentially leading to convective collaps...

In the present study, the possibility of concentrating tungsten-copper vein ore in South Chah-Palang was examined using gravity separators including Jig Machine (-2360+600 μm), shaking table (-600+120 μm), and multi-gravity separator (MGS) (-120 μm). The representative sample contains 1.5% WO3 and 5.95% CuO. The main tungsten minerals were ferberite and wolframite and their appropriate liberati...

A capillary flow liquid acquisition device (LAD) for cryogenic propellants has been developed and tested in NASA Glenn Research Center to meet the requirements of transferring cryogenic liquid propellants from storage tanks to an engine in reduced gravity environments. The prototypical mesh screen channel LAD was fabricated with a mesh screen, covering a rectangular flow channel with a cylindri...

OBJECTIVE Assess the performance of self-expanding venous cannulas for routine use in open-heart surgery. METHODS Prospective study in 100 unselected consecutive patients undergoing open-heart surgery with either remote or central smart venous cannulation. RESULTS The study focuses on the 76 consecutive adult patients (mean age 59.2+/-17.3 years; 60 males, 16 females) undergoing surgical pr...

The flow of blood through the cardiovascular system depends on basic principles of liquid flow in tubes elucidated by Bernoulli and Poiseuille. The elementary equations are described involving pressures related to velocity, acceleration/deceleration, gravity, and viscous resistance to flow (Bernoulli-Poiseuille equation). The roles of vascular diameter and number of branches are emphasized. In ...

This paper investigates the impact of the US and China’s foreign aids to Africa on trade flows between donor and recipient countries. Evidence from the gravity model estimates reveals that the two donors’ exports are strengthened by their aids to African partners. Interestingly, China’s aid shows a positive effect on its total volume of trade and imports from Africa, while the aid from the US e...

Using a gravity model, we estimate the magnitude of potential trade flows between Ireland and the five CEEC countries which are currently negotiating accession to the EU. We find that Irish exports were already close to their “normal” level in 1994, but that imports from the CEECs were still less than half of their potential size. The value of estimated potential trade corresponds to 0.8 per ce...

The Southern timber market is the major source of both softwood and hardwood pulpwood in the US. In 1997, three-fourths of total US pulpwood production was produced in the region. The locations of pulpmills and fiber sources determine the patterns of pulpwood trade between the states. Prediction of trade is important for understanding subregional pulpwood markets in the US South and for timber ...